var myrules = {

    '#header A IMG' : function(element){

      element.onmouseover = function(){

        if (element.id != "active") {

          var src = element.src;

          var arr = src.split("/");

          arr = arr[arr.length-1].split(".gif");



          var img = arr[0];

          arr = img.split("_");

          img = "";





          for (var i = 0; i < arr.length-1; i++) {

            if (arr[i].length && img)

              img += "_";

            img += arr[i];

          }



          element.src = "images/menu/"+img+"_on.gif";

        }

      },

      element.onmouseout = function(){

        if (element.id != "active") {

          var src = element.src;

          var arr = src.split("/");

          arr = arr[arr.length-1].split(".gif");



          var img = arr[0];

          arr = img.split("_");

          img = "";





          for (var i = 0; i < arr.length-1; i++) {

            if (arr[i].length && img)

              img += "_";

            img += arr[i];

          }



          element.src = "images/menu/"+img+"_off.gif";

        }

      }

    }

  };



  Behaviour.register(myrules);